Jacki
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Hi,
I face a ringing problem for trans-impedance amplifier. Actually it is not oscillation, it looks like overshooting. But the Opamp in TIA has enough phase margin (80 degree). I cannot figure it out. In the book, usually the phase margin is defined for voltage source, I don't know if it could be used for current source.
But if I change current source to voltage source as shown in the figure, I don't have any problem of ringing (overshooting). Because the phase margin of loop gain is around 80 degree, I can see the overdamping for voltage source.
Could anyone give me some comments?
Thank you.
Jacki.
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